Test Report: Ergonomic Evaluation of 3D Mice

Introduction D mice pro ide support for manipulating and na igating

in AD applications. Fraunhofer Institute for Industrial Engineering IAO as as ed Dconne ion m H to conduct a scientific stud assessing the ergonomic ene-fits of or ing ith a Space ouse Enterprise. Health related issues such as the strain of the hand-arm-s stem and the impact on the sitting posture as ell as the usa-ilit and user e perience ere e amined. Finall , the

effect on the producti it as anal ed under la orator conditions.

ethodolog he stud as split into a la orator stud and a field

stud . he goal of the la orator stud as to measure and o ser e human factors issues, health-related issues as ell as producti it . his part of the stud as con-ducted ith 1 engineering students of an ad anced

AD course at the ni ersit of Stuttgart. he partici-pants ere on a erage 2 ears old, 2 female, 12 male, all used the mouse ith the right hand, although onl 12

ere right-handed, 2 ears of AD e perience, and none used a D mouse for more than testing purposes efore.

he participants recei ed a standardi ed and randomi ed AD tas to e sol ed under o ser ation ith a tradi-

tional setup of e oard and mouse in 10. After a training period of one ee ith a pro ided D mouse, a second, similar tas as gi en to e sol ed ith a D mouse. he t o tas s ere of similar difficult ut re-uired a different set of tools to sol e. During the tas s

all mouse mo ements and clic s ere logged as ell as the od posture monitored see Figures 1 and 2 .

he field stud as aimed to ards professionals or ing ith AD soft are on a dail asis. he participants ere on a erage 8 ears old, 2 female, 8 male, all ere

right-handed, 1 ears of AD e perience 0. 0 ears , hours of AD per da , alread used a D

mouse Dconne ion, the participants or as either engineers, designers, or consultants.

his part of the stud relied on semi-structured inter ie s as ell as the standardi ed and alidated uestionnaires S Si and Attra Diffii. Similar to the la orator stud the t o conditions of or ing ith and ithout a D mouse

ere e amined. he four participants alread using a D mouse stopped or ing ith it for three ee s. o the si participants not using a D mouse efore, a Space-

ouse Enterprise as pro ided. he inter ie s ere conducted efore and after this three- ee change of de ices.

esults t

here is strong e idence that using a D mouse leads to healthier sitting posture upright and supported the chair caused ha ing oth arms on the des hile

or ing in a AD application sho n in Figure 2 as an e ample for one test su ect . he positi e effect in posture is supported ans ers gi en in the field inter-ie s.

As the D mouse ta es o er tas s traditionall done ith the right-hand mouse, the load on the right hand-arm-

with 3D mousewithout 3D mouse

Figure 2 Change in sitting postureFigure 1 Two participants working on a CAD task while the postures are being monitored

i Brooke, J. (1986). SUS: a “quick and dirty“ usability scale. Usability Evaluation in Industry. London: Taylor and Francis. ii Hassenzahl, M., Platz, A., Burmester, M. & Lehner, K. (2000). Hedonic and ergonomic quality aspects determine a software's appeal. Proceed-

ings of the CHI 2000 Conference on Human Factors in Computing. The

Hague, NLiii Salvendy, G. (2012). Handbook of human factors and ergonomics (pp. 828-836). New York, USA: John Wiley & Sons, Inc.

0

500

1000

1500

2000

w/o 3D mouse w/ 3D mouse

Clicks left Clicks middle Clicks right Mouse wheel

Figure 3 Finger movements per hour t(13)=2.52, p=0.028

974

5032280

1336

1001

132 49

690

1872 “Dangerous amount of hand

movement”iii

with a SUS score of 86.3 compared to an only OK level of usability (SUS: 62.3) for the traditional workflow with keyboard and normal mouse.

The AttrakDiff questionnaire shows a very high level of user experience, with a high hedonic (“Is the product appealing?”) and pragmatic (“Does the user achieve his goals?”) quality as well as a high level of attractiveness for the end user.

After 1.5 weeks, five out of six participants described working with the 3D mouse as moderately difficult; after three weeks, five out of six participants described it as easy or very easy. The CAD experience was described as more “fluid” and more “harmonic” using the 3D mouse.

Participants using a 3D mouse for the first time (both in the laboratory and the field study) reported that the direction of the controller cap axes was not intuitive at first use. These users could benefit from better instructions on how to use the controller cap of the 3D mouse. Furthermore, the allocation of function keys to the explaining pictograms of the ondevice screen could be optimized by reducing the space between the two areas.

Summary Overall the SpaceMouse Enterprise leads to a healthier posture and reduces the workload for the dominant hand-arm-system. It shows a high level of usability and makes working with CAD applications demonstrably more productive.

Stuttgart, 01.09.2018

system is reduced significantly. The number of mouse wheel movements (used in NX to zoom in and out of the model) is reduced significantly (t(13)=2.52, p=0.028), leading to a total reduction of finger movements by 28.6% (see Figure 3). This reduces the amount of finger movements from a “dangerous” level (over 1500 move-ments/houriii) to an acceptable level.

The amount of mouse clicks and distance covered by the mouse was not reduced significantly during the labo-ratory study. However, it is expected that the amount and distance is reduced in a professional setting as the function keys are used more frequently and the traditional mouse is used less for navigating inside of the CAD application’s menus. This hypothesis was confirmed during the field study by all participants, stating that the load is distributed more evenly on both hands. Three participants who had a tenosynovitis in the right arm reported decreased strain by using a 3D mouse.

Productivity

The productivity could be increased significantly under the condition of using the 3D mouse. The time necessary to solve the randomized task went down by 28% (from 96 minutes to 68 minutes to solve each task; t(13)=5.28, p<0.001) using a 3D mouse in the laboratory study. Two confounding factors may have influenced this result in both directions: the test subjects may have gotten faster using the CAD application due to more training. On the other hand, one week of part-time training is not enough to take full advantage of the 3D mouse and its functions, slowing the participants down.

In a professional setting the productivity between multi-ple workstations can be raised by providing a more effi-cient way of transferring the personal settings between multiple work spaces. For beginners the tutorial should be advertised more prominently and should go into greater detail to make the first steps easier.

Usability and User Experience

The workflow of using the SpaceMouse Enterprise in a professional setting shows an excellent level of usability

Dipl.-Ing. Harald Widlroither,

Head of Human Factors Engineering

Fraunhofer Institute for Industrial Engineering IAO